{"artifact_id":"L1-436","layer":"L1","title":"Ensemble Kalman Filter (EnKF)","domain":"Control Theory","sub_domain":"Ensemble data assimilation","physics_fingerprint":{"L_DAG":3.5,"title":"Ensemble Kalman Filter (EnKF)","domain":"Control Theory","carrier":"N/A","primitives":["S.enkf.ensemble_update","O.regularize","O.inflation.ensemble_spread"],"sub_domain":"Ensemble data assimilation","noise_model":"gaussian","problem_class":"parameter_estimation","solution_space":"ensemble_state_distribution","difficulty_delta":5,"integration_axis":"assimilation_cycle","sensing_mechanism":"ensemble_state_estimation"},"observable_profile":{"metric":"spread_skill_ratio","regime":"Existence of the recovered ensemble_state_distribution is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by declared priors. Stability is conditionally stable (kappa_eff ~= 500); sampling_error_finite_ensemble dominates the stability cliff; the remaining mismatch parameters contribute higher-order bias terms. Gaussian sets the irreducible data-fidelity floor.","secondary":"RMSE_analysis_normalized"},"size_tiers":{"center_spec":{"omega":{"N_e_ensemble":50,"localization_km":500,"n_state_million":1,"obs_density_per_gridpt":0.1},"input_format":"measurement_only","problem_class":"parameter_estimation","forward_operator":"ensemble_state_estimation","epsilon_fn_center":"0.05 RMSE_analysis_normalized"},"omega_bounds":{"N_e_ensemble":[10,1000],"localization_km":[50,5000],"n_state_million":[0.001,100],"obs_density_per_gridpt":[0.01,10.0]},"epsilon_bounds":{"RMSE_analysis_normalized":[0.01,0.3]},"allowed_problem_classes":["parameter_estimation"],"allowed_omega_dimensions":["N_e_ensemble","n_state_million","obs_density_per_gridpt","localization_km"],"allowed_forward_operators":["ensemble_state_estimation"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":10000.0,"metric":"spread_skill_ratio"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x9007e2f6a5fc7308d9ca5e457cceb718b8a8c4631fa95bb6faf3a502ae64ed00","chain_tx_hash":"0x0aedcdc01c4f114a8b81dde23900d09f2d90d0e5e47d90d3a70935b94361dd08","chain_block":41555258}